640738016 has 12 divisors (see below), whose sum is σ = 1261453032. Its totient is φ = 320368992.

The previous prime is 640738013. The next prime is 640738019. The reversal of 640738016 is 610837046.

It is an interprime number because it is at equal distance from previous prime (640738013) and next prime (640738019).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640738013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10011500 + ... + 10011563.

It is an arithmetic number, because the mean of its divisors is an integer number (105121086).

Almost surely, 2^640738016 is an apocalyptic number.

It is an amenable number.

640738016 is a deficient number, since it is larger than the sum of its proper divisors (620715016).

640738016 is a wasteful number, since it uses less digits than its factorization.

640738016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20023073 (or 20023065 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 640738016 is about 25312.8034006508. The cubic root of 640738016 is about 862.1050002817.

The spelling of 640738016 in words is "six hundred forty million, seven hundred thirty-eight thousand, sixteen".